Batteries
During the last couple of days I learned more about batteries on World Book Online.
Battery is a device that stores energy as chemical energy and releases it as electric energy. Chemical reactions in a battery create an electric current. Electric currents from batteries can power many devices from tiny portable electronics to large automobiles.
The first ever primitive battery was discovered  in 250 B.C. It contained an iron rod and a copper cylinder that could have functioned as electrodes.
The first documented working cell was made around 1800 by Alessandro Volta, an Italian scientist.
In the early 1830’s an English scientist named Michael Faraday showed that oxidation and reduction reactions create the force that pushes an electric current.  In 1836, John F. Daniell, an English chemist introduced a more efficient primary cell that used copper and zinc. In 1859, the French physicist Gaston Plante invented the first secondary battery. It used lead-acid chemistry.
How a battery works?
An electric current consists of tiny particles called electrons. Usually electrons form part of atoms. A battery works by separating electrons from atoms in the battery’s material and pushing them into an electric circuit. A circuit is a looping path through which electric current travels. The flow of electrons through the circuit forms a current. Battery-powered devices, in turn, can be connected to the circuit. These devices change the electric energy of the current into other useful forms of energy. There are two electrodes also called poles. The first electrode, called the anode is marked with a minus sign −. It releases electrons into the circuit. The electrons flow around the circuit and power any connected devices. The electrons reenter the battery through the second electrode, the cathode. The plus sign +.
Last time I Used A Battery
The last time I used batteries was  two weeks ago when I built my own robot. It has two batteries connected to two switches and two motors that make it move.  The main body is made from cardboard. 
Where I got my materials from?
A few months ago I hacked open 2 broken remote controlled cars. I wondered what would I find inside. I got the motors scrap wires and switches. I asked my parents for a few batteries to see if the motors still worked. I played with that for a few weeks and  stopped. The day before Easter I wanted to build something new using the motors, so I came up with the idea to build something that drives. On my first attempt it had cardboard wheels and everything was attached with elecrtical tape . When I did a test drive I was suuupper happy: it drove! But it didn't drive very fast. An hour later my mom came up with the idea to put Lego wheels on it. When I was done putting them on and did another test drive, it went so much faster! When everything was perfect I asked my dad if I could use his soldering iron and solder everything into place. So I went to the shed and started to solder (obviously with adult supervision! If you were wondering:) ). When I was done about 15 minutes later, I could not stop playing with my new robot. I attached a photo and a short video with my build.